title: Evidence of Polymorphism on the Antitrypanosomal Naphthoquinone (4E)-2-(1H-Pyrazol-3-ylamino)-4-(1H-pyrazol-3-ylimino)naphthalen-1(4H)-one.
abstract: The aim of this study was to characterize the solid state properties of (4E)-2-(1H-pyrazol-3-ylamino)-4-(1H-pyrazol-3-ylimino)naphthalen-1(4H)-one (BiPNQ), a compound with a significant inhibitory activity against Trypanosoma cruzi, the etiological agent of Chagas disease (American trypanosomiasis). Methods used included Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Fourier Transform Infrared Spectroscopy (FTIR), Powder X-Ray Diffraction (PXRD), Hot Stage, and Confocal Microscopy. Two BiPNQ samples were obtained by crystallization from absolute methanol and 2-propanol-water that exhibited different thermal behaviours, PXRD patterns, and FTIR spectra, indicating the existence of an anhydrous form (BiPNQ-I) and a solvate (BIPNQ-s), which on heating desolvated leading to the anhydrous modification BiPNQ-I. It was determined that FTIR, DSC, and PXRD are useful techniques for the characterization and identification of the crystalline modifications of BiPNQ.
authors.affiliation: Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA, Córdoba, Argentina.
authors.forename: Norma R
authors.initials: NR
authors.lastname: Sperandeo
authors.forename: Sonia N
authors.initials: SN
authors.lastname: Faudone
keywords: Chagas disease; DSC; Polymorphism; Powder X-ray Diffraction; Pyrazolylnaphthoquinones; TG